Page 26 - 2018_IMC

CHAPTER 2

DEFINITIONS

User note:
About this chapter: Codes, by their very nature, are technical documents. Every word, term and punctuation mark can add to or change the
meaning of a technical requirement. It is necessary to maintain a consensus on the specific meaning of each term contained in the code.
Chapter 2 performs this function by stating clearly what specific terms mean for the purposes of the code.

SECTION 201 tribution of the air to meet the requirements of a conditioned
GENERAL space.
201.1 Scope. Unless otherwise expressly stated, the follow- AIR-CONDITIONING SYSTEM. A system that consists
ing words and terms shall, for the purposes of this code, have of heat exchangers, blowers, filters, supply, exhaust and
the meanings indicated in this chapter. return ducts, and shall include any apparatus installed in con-
nection therewith.
201.2 Interchangeability. Words used in the present tense
include the future; words in the masculine gender include the AIR DISPERSION SYSTEM. Any diffuser system
feminine and neuter; the singular number includes the plural designed to both convey air within a room, space or area and
and the plural, the singular. diffuse air into that space while operating under positive pres-
sure. Systems are commonly constructed of, but not limited
201.3 Terms defined in other codes. Where terms are not to, fabric or plastic film.
defined in this code and are defined in the International
Building Code, International Fire Code, International Fuel AIR DISTRIBUTION SYSTEM. Any system of ducts, ple-
Gas Code or the International Plumbing Code, such terms nums and air-handling equipment that circulates air within a
space or spaces and includes systems made up of one or more
shall have meanings ascribed to them as in those codes.
air-handling units.
201.4 Terms not defined. Where terms are not defined AIR, EXHAUST. Air being removed from any space, appli-
through the methods authorized by this section, such terms ance or piece of equipment and conveyed directly to the
shall have ordinarily accepted meanings such as the context atmosphere by means of openings or ducts.
implies.
AIR-HANDLING UNIT. A blower or fan used for the pur-
pose of distributing supply air to a room, space or area.
SECTION 202 AIR, MAKEUP. Any combination of outdoor and transfer
GENERAL DEFINITIONS air intended to replace exhaust air and exfiltration.
AIR, OUTDOOR. Ambient air that enters a building
ABRASIVE MATERIALS. Moderately abrasive particulate
in high concentrations, and highly abrasive particulate in through a ventilation system, through intentional openings for
moderate and high concentrations, such as alumina, bauxite, natural ventilation, or by infiltration.
iron silicate, sand and slag. AIR, TRANSFER. Air moved from one indoor space to
another.
ABSORPTION SYSTEM. A refrigerating system in which
refrigerant is pressurized by pumping a chemical solution of [A] ALTERATION. A change in a mechanical system that
refrigerant in absorbent, and then separated by the addition of involves an extension, addition or change to the arrangement,
heat in a generator, condensed (to reject heat), expanded, type or purpose of the original installation.
evaporated (to provide refrigeration), and reabsorbed in an APPLIANCE. A device or apparatus that is manufactured
absorber to repeat the cycle; the system can be single or mul- and designed to utilize energy and for which this code pro-
tiple effect, the latter using multiple stages or internally cas- vides specific requirements.
caded use of heat to improve efficiency.
APPLIANCE, EXISTING. Any appliance regulated by this
ACCESS (TO). That which enables a device, appliance or code that was legally installed prior to the effective date of
equipment to be reached by ready access or by a means that this code, or for which a permit to install has been issued.
first requires the removal or movement of a panel or similar APPLIANCE TYPE.
obstruction [see also “Ready access (to)”].
High-heat appliance. Any appliance in which the prod-
AIR. Air supplied to mechanical equipment and appliances ucts of combustion at the point of entrance to the flue
for combustion, ventilation, cooling and similar purposes. under normal operating conditions have a temperature
Standard air is air at standard temperature and pressure, greater than 2,000ºF (1093ºC).
namely, 70ºF (21ºC) and 29.92 inches of mercury (101.3 Low-heat appliance (residential appliance). Any appli-
kPa).
ance in which the products of combustion at the point of
AIR CONDITIONING. The treatment of air so as to control entrance to the flue under normal operating conditions
simultaneously the temperature, humidity, cleanness and dis- have a temperature of 1,000ºF (538ºC) or less.

2018 INTERNATIONAL MECHANICAL CODE  9
Copyrighted © 2017 by, or licensed to, ICC (ALL RIGHTS RESERVED); licensed to UL, LLC pursuant to License Agreement with ICC. No further reproductions authorized or distribution authorized.
ANY UNAUTHROIZED REPRODUCTION OR DISTRIBUTION IS A VIOLATION OF THE FEDERAL COPYRIGHT ACT AND THE LICENSE AGREEMENT; AND SUBJECT TO CIVIL AND CRIMINAL PENALTIES THEREUNDER.